/**
 * @version: V1.0
 * @Title: WidthForEach.java
 * @Description:
 * @author wangshipeng
 * @date 2022-01-20 23:17
 * @Copyright: 2022-01-20
 */

package com.peng.tree.foreach;

import com.peng.tree.Node;

import java.util.LinkedList;
import java.util.Queue;

/**
 * @author wangshipeng
 * @ClassName: WidthForEach
 * @Description: 按层，即广度优先遍历
 * @date 2022-01-20 23:17
 */
public class WidthForEach {

    public static void foreach(Node head) {
        if (head == null) {
            return;
        }
        Queue<Node> queue = new LinkedList<>();
        queue.add(head);
        while (!queue.isEmpty()) {
            Node cur = queue.poll();
            System.out.println(cur.value);
            if (cur.left != null) {
                queue.add(cur.left);
            }
            if (cur.right != null) {
                queue.add(cur.right);
            }
        }
    }

    public static void main(String[] args) {
        Node node = new Node(1);
        Node node2 = new Node(2);
        Node node3 = new Node(3);
        Node node4 = new Node(4);
        Node node5 = new Node(5);
        Node node6 = new Node(6);
        Node node7 = new Node(7);
        Node node8 = new Node(8);
        Node node9 = new Node(9);

        node.left = node2;
        node.right = node3;
        node2.left = node4;
        node2.right = node5;
        node3.left = node6;
        node3.right = node7;
        node4.left = node8;
        node4.right = node9;

        /*
                   1
             2              3
           4   5         6     7
         8   9

         */

        foreach(node);


    }

}
